Giancarlo Stanton Yankees
Giancarlo Stanton #27 of the New York Yankees follows through on a first inning two-run home run against the Tampa Bay Rays at Yankee Stadium on April 4, 2018 in the Bronx borough of New York City. He's helped the New York Yankees get off to a fast start in the 2018 MLB season. Jim McIsaac/Getty Images

The 2018 MLB season is officially a week old, meaning there is still more than 95 percent of the year left to be played. Every game counts the same, however, and getting off to a strong start can go a long way in making a run to the playoffs.

Most of the American League’s top World Series contenders are at the top of the early standings. The defending champion Houston Astros (6-1) have the best record in baseball, and they are followed by the AL East champion Boston Red Sox (5-1). The New York Yankees (4-2) are a game out of first place.

Four of last year’s five AL playoff teams have a winning record in the early going. The Cleveland Indians (2-4) are the only exception.

In the National League, the teams with the highest expectations are struggling. The Los Angeles Dodgers (2-5) are just a half-game out of last place in the NL West. The same goes for the Chicago Cubs (2-3) in the NL Central. L.A. and Chicago began the year with the best World Series odds in the NL.

The Arizona Diamondbacks (5-1) and Washington Nationals (4-2) are the only NL playoff teams that sit above .500. None of last year’s NL division winners are in first place.

The Pittsburgh Pirates (5-1) have to be considered the biggest surprise of the first week. After trading their two best players in the offseason, the team sits atop a division that’s supposed to have several playoff contenders.

The New York Mets (4-1) are also off to a good start as they look to bounce back from a bad year. They’ve got the NL’s second-best ERA behind strong performances from Matt Harvey and Jacob deGrom.

Shohei Ohtani has gotten off to a historic start to the season with the Los Angeles Angels (5-2). The rookie has picked up a win as a starting pitcher in addition to hitting .429 with two home runs in 14 at-bats.

Four teams have at least five wins, and the Angels are the only team in that group that missed the postseason a year ago. Six teams have just one victory, and none of them had a winning record in 2017.